Should I flush Radiator

[swsandy]

Should I flush coolant that is at least four years old but looks perfect? I have a 2003 Ranger and a 2002 Explorer both with 4.0L. The Explorer needed a coolant flush, it had been awhile and it looked grubby so I bought four gallons of Zerex G-05 figuring I'd just do both vehicles (it was a good deal on sale). I've owned the Ranger for four years and it has never had the coolant flushed but when I opened the cap it all looked pristine. Now I'm wondering if it is worth changing it. Any opinions?

 

[974X4BLACKSPORT]

If you dont know the service history of the cooling system, then it would be a good idea to change it and get it on "record" as new coolant so you can be keep track of it.

 

[Drewmcg]

Just be sure you get all of the old coolant out, since '02 was a transition year and it does not play well with the old stuff. I swapped Zerex G-05 (same as Motorcraft "gold") after I replaced radiator and water pump, since that stuff lasts a lot longer than the older coolant. But it does not mix well with others. And I had to fight off mechanics, etc., who would try to top it off with "universal" coolant--thereby defeating the purpose of a 3-5 year, 150k miles coolant like the G-05.